Device handling system and method

ABSTRACT

An apparatus and method for handling devices adapted to be assigned to one of a plurality of categories are disclosed. The apparatus includes an elevator adapted to move a stack of trays along a vertical path, a locking mechanism adapted to selectively engage a tray in the stack of trays and to support the engaged tray and additional trays positioned above the engaged tray, and a tray load arm positioned at a fixed vertical position and having a support mechanism for supporting one or more trays, the tray load arm being adapted to move horizontally into and out of the vertical path.

This application claims the benefit of U.S. Provisional Patent Application No. 60/546,103, titled “MODULAR VERTICAL TRAY-SORTING APPARATUS WITH INTEGRAL OPERATOR LOAD/UNLOAD INTERFACE,” filed Feb. 18, 2004, which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of device handling. In particular, the invention relates to methods and systems for handling devices that are sorted into a plurality of categories.

Device handlers are typically used to supply electronic devices to a tester, which may perform any of a variety of tests upon the electronic devices. For example, the tester may determine the actual processor speed of a chip. Once the electronic device is tested, it may be categorized into one of a plurality of categories based on the tested characteristics. The device handler may then sort the electronic devices according to these categories.

Conventional handlers are very expensive and occupy a large amount of floor space in the manufacturing facility. In a conventional system for handling devices in a testing environment, the sort bins are horizontally located with respect to each other. In such a system, a pick-and-place head must move horizontally a great distance in order to place a tested electronic device in one of a plurality of bins corresponding to its performance characteristics. As the number of sort category bins increases, the travel time required for the second pick-and-place head to place an electronic device into a sort category bin increases to unacceptable levels. In addition, the size of the handling machine, known as a footprint, increases dramatically because each additional sort category increases the footprint.

Further, in conventional handling systems, an operator typically loads a stack of input trays containing electronic devices to be sorted. When the sorting of the stack is completed, the operator must manually remove the sorted stack and insert a new stack of input trays. While the operator is performing these tasks, the tester may be unable to operate, leading to substantial downtime.

SUMMARY OF THE INVENTION

One embodiment of the invention relates to an apparatus for handling devices adapted to be assigned to one of a plurality of categories. The apparatus includes an elevator adapted to move a stack of trays along a vertical path, a locking mechanism adapted to selectively engage a tray in the stack of trays and to support the engaged tray and additional trays positioned above the engaged tray, and a tray load arm positioned at a fixed vertical position and having a support mechanism for supporting one or more trays, the tray load arm being adapted to move horizontally into and out of the vertical path.

Another embodiment of the invention relates to a method of sorting a tray of devices adapted to be assigned to one of a plurality of categories. The method includes receiving a sorted tray of devices assigned to one of the categories, determining a sort position for the sorted tray in a stack of trays on a platform, vertically moving the platform to align a locking mechanism with an upper tray in the stack immediately above the sort position, locking the upper tray with the locking mechanism, vertically moving the platform to position a lower tray below a load arm having the sorted tray, the lower tray being immediately below the sort position; and placing the sorted tray on the lower tray on the platform.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and exemplary only, and are not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a device testing system including a device handling system according to an embodiment of the invention;

FIG. 2 is a top view of a device handler according to one embodiment of the invention;

FIG. 3 is a top view of a device handler according to another embodiment of the invention;

FIG. 4A is a perspective illustration of a modular binning load port (BLP) for a device handler according to an embodiment of the invention;

FIG. 4B is a perspective illustration of a modular binning load port (BLP) for a device handler according to another embodiment of the invention;

FIGS. 5A and 5B are perspective front views of the BLP of FIG. 4A with certain panels removed;

FIG. 6A illustrates an embodiment of a modular system having four BLP units;

FIGS. 6B and 6C illustrate the interface points of the modular system shown in FIG. 6A;

FIGS. 7A and 7B illustrate front and side views, respectively, of an elevator mechanism according to an embodiment for positioning trays of electronic devices;

FIG. 8A-8L illustrate the operation of various functions performed by a device handler according to an embodiment of the invention;

FIG. 9 is a perspective illustration of a tray for transporting devices using a device handler according to an embodiment of the invention; and

FIG. 10 illustrates category separator plates for use with a device handler according to an embodiment of the invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Referring to FIG. 1, a block diagram of a device testing system 10 is illustrated. The device testing system 10 includes a device handling system 11 in accordance with the invention. The device testing system 10 and the device handling system 11 may be adapted to test and handle devices such as electronic devices including integrated circuits, semiconductor chips, transistors, microprocessors, diodes, hybrid circuits, memory chips, for example. The device handling system 11 includes an input and sort system 12 for providing untested devices to a tester 20 and for sorting devices tested by the tester 20 according to a plurality of categories.

In certain embodiments, the input and sort system 12 includes a plurality of horizontally arranged category tray locating stations in combination with a vertical binning load port 13. In this manner, the tested devices may first be placed in trays corresponding to various categories. When those trays are filled, the trays are transferred to an appropriate position in the vertical binning load port 13. One such embodiment is described below with reference to FIG. 2.

In other embodiments, the input and sort system 12 is a vertical handling system similar to the binning load port described above. In this regard, the horizontally arranged category tray locating stations are not required. Instead, the devices are directly placed into an appropriate position in a stack of vertically sorted trays. One such embodiment is described below with reference to FIG. 3.

Referring again to FIG. 1, a transfer system 14 is provided to pick up untested devices from input trays and place the untested devices into a load station 16. The untested devices in the load station 16 may be transported to a thermal conditioner 18 in preparation for testing in the tester 20, as is known in the art. The transfer system 14 may also pick up tested devices at the load station 16 and place the tested devices into one of a plurality of sort categories, based on the results of the testing.

The tester 20 may test each device, may then assign a sort category code to each of the devices based on the testing criteria, and may then return the devices for transport to the load station 16 through a queuing conveyor 22. In the case of electronic devices, the devices may be tested for various functional characteristics and then be sorted into a particular category based on, for example, the speed or the functionality of the particular electronic device. The invention is not limited to any particular type of testing system or any particular type of device.

The testing system 10 is preferably controlled by a processor 24 that may be connected to each of the systems within the testing system 10. The processor 24 may also be contained within the device handling system 11 or the input and sort system 12.

Referring now to FIG. 2, a top view of an embodiment of a device handling system 11 is illustrated in conjunction with a device tester 20. In other embodiments, the device handling system 11 may operate without a device tester 20 and with any of numerous types of other equipment. The illustrated embodiment of the device handling system 11 includes an input and sort system which includes a plurality of tray locating stations 28. Each tray locating station 28 corresponds to either input, buffer or a sort category. An input pick-and-place mechanism 30 is provided to deliver devices to be tested from an input tray in one of the tray locating stations 28 to the tester 20. An output pick-and-place mechanism 32 is provided to return the tested devices to a tray in a tray locating station 28 corresponding to a sort category. Each pick-and-place mechanism 30, 32 is capable of two dimensional movement in a substantially horizontal plane, in addition to limited vertical movement for picking and placing of devices. The sort categories in the various tray locating stations 32 either may be predetermined or may be dynamically assigned as needed.

A tray handling shuttle 26 is provided to transport a tray between the tray locating stations and one or more vertical sort binning load ports (BLP's). Other embodiments may include additional tray handling shuttles at various stations. The tray handling shuttle 26 is positioned below or above the tray locating stations 28, but is shown outside the device handling system 11 in FIG. 2 for purposes of clarity. The trays, such as tray 27, transported by the tray handling shuttle 26 may be empty, contain untested devices or contain sorted devices.

The embodiment illustrated in FIG. 2 includes four BLP units 13. It will be apparent to those skilled in the art that any practical number of BLP units 13 may be used depending on the particular use. The device handler 11 may be capable of mating to one or more BLP units 13 via a standard docking interface and communications protocol between the device handler 11 and the BLP 13.

In operation of the system illustrated in FIG. 2, an operator may load one or more BLP units 13 with a stack of trays of untested devices and empty trays. A control processor, such as processor 24 shown in FIG. 1, may control the operation of the tester 20 and the device handler 11. In this regard, a specified tray (e.g., empty or untested) may be requested from one of the BLP units 13. The BLP unit 13 then provides a tray from the stack of trays through the use of a tray load arm, as described below with reference to FIG. 4A. The tray shuttle 26 may transport the tray from the BLP unit 13 and place it in one of the tray locating stations 28, where it can be accurately positioned and held. The input pick and place mechanism 30 removes individual devices from the tray and transports to the device tester 20. After each device is tested, the output pick and place mechanism 32 transports the device from the device tester 20 and places it in a tray corresponding to the category assigned by the tester 20. Trays may be automatically presented to the device handler 11 and the device tester 20 and may be sorted as described above.

Once a tray in one of the tray locating stations 28 has been filled with tested devices, the filled tray can be removed by the tray shuttle 26 and inserted into one of the BLP units 13.

In one embodiment, the tray is returned to the same BLP unit 13 from which it was removed. The BLP unit 13 places the tray in a vertically sorted position corresponding to the test category of the devices in the tray. Device processing may continue until all devices from a single BLP unit 13 have been tested and sorted back into the same BLP unit 13. At this time, the device testing system 10 may start processing devices from the next available BLP unit.

As an alternative to using a single BLP, the incoming trays can be distributed between multiple BLP units and the tray handling system will retrieve and sort trays to all associated BLP units as necessary.

Once all devices in a particular BLP unit 13 have been completely tested and sorted, that BLP unit can now be available for unload and reload by an operator. Any time a BLP unit is open for operator interaction it may be interlocked such that the tray shuttle 26 will not be able to enter an enclosure of that particular BLP unit 13.

FIG. 3 illustrates a top view of a second embodiment of a device testing system. In this embodiment, the device handling system 11 is provided with a vertical input and sort system 12 similar to the BLP unit of the embodiment of FIG. 2 and described in detail below. An input tray may be presented directly from the vertical input and sort system 12 which has been loaded with a stack of trays containing untested devices. Once an individual device is tested, it is placed directly into an appropriate tray in the vertically sorted stack of trays in the vertical input and sort system 12. In this regard, the horizontally arranged category tray locating stations shown in FIG. 2 are not required.

FIG. 4A illustrates an exemplary BLP unit 13. The BLP unit 13 includes a tray load arm 34 which can slide into and out of the BLP unit 13. Specifically, the tray load arm 34 can move between a vertical path of an elevator inside the BLP unit 13 and a loading/unloading position substantially outside the BLP unit 13. In this regard, the tray load arm 34 is ergonomically positioned to allow an operator to load or unload a stack of trays 36. Since loading and unloading trays is done externally to the BLP unit 13, the device testing system (not shown in FIG. 4A) to which the BLP unit 13 is attached can continue processing devices from other BLP units without interruption. This increases the number of devices processed per unit time. As noted above, the stack of trays 36 may contain trays that are empty, loaded with untested devices or loaded with tested and sorted devices. In the rear of the BLP unit 13, a single tray 27 may be exchanged between the BLP unit 13 and, for example, a device testing system (not shown). In this regard, the tray handling shuttle 26 described above with reference to FIG. 2, may be used to remove trays from the BLP unit 13 and to transport tested and sorted trays from the testing system (not shown) to the BLP unit 13.

FIG. 4B illustrates another embodiment of a BLP. The BLP 13 a illustrated in FIG. 4B includes an automated conveyor 35 which allows automated loading and unloading of trays. In this regard, the BLP 13 a may function in conjunction with an external device adapted to interface with the BLP. The external device (not shown) may be adapted to supply untested trays to the BLP 13 a for testing, for example. The tested and sorted trays may be removed from the BLP 13 a in an automated manner through the automated conveyor 35.

The automated conveyor 35 may include a conveyor belt adapted to transport a stack of trays between devices. The conveyor belt can be driven by a motor adapted to turn drive rollers positioned under the conveyor belt. Such conveyor systems are well known to those skilled in the art.

FIGS. 5A and 5B illustrate the BLP unit 13 of FIG. 4A in greater detail with certain panels removed. The BLP unit 13 includes an elevator 38 adapted to position a tray stack and separator plates vertically in the system. Separator plates are a specific type of tray which may not include any devices and will be described below in greater detail with reference to FIGS. 8A-8L. A plate lock mechanism 40 is provided to lock and hold a set of trays or category separator plates in a specified position. The BLP unit 13 includes the tray load arm 34 for separating and holding trays of devices, as well as allowing an operator to insert and extract trays from the BLP unit 13. The tray load arm 34 is supported by a bearing rail 44 extending horizontally at a desired height. The height is generally set so as to allow ergonomic positioning of the tray load arm 34 when accessed by an operator.

A set of lower vertical tray guides 42 is provided to limit lateral displacement of the trays during various operations. In this regard, the guides 42 ensure proper alignment of the trays for engagement by various components, as described below with reference to FIGS. 8A-8L. A set of upper tray guides 46 are provided to laterally constrain the trays and separator plates during various operations when they are above the plate lock mechanism 40.

The elevator 38 is moved in the vertical direction by a drive motor 48. The drive motor 48 may be an electric motor. In the illustrated embodiment, a ball-screw assembly is provided to transfer energy from the drive motor 48 to the elevator 38. The elevator 38 may be supported by an elevator-bearing rail 50 which allows movement of the elevator 38 in the vertical direction.

As described in FIG. 2 above, an embodiment of the BLP unit 13 provides a modular platform. In this regard, as illustrated in FIG. 6A, a plurality of BLP units 13 may be used in a system 52 wherein a processing component 54 can be changed as desired by the end user. Thus, each BLP unit 13 is provided with a substantially identical mechanical and electrical interface and is externally docked to the processing component. Thus, the BLP unit 13 may be interchangeably used with any number of processing components. In the embodiment illustrated in FIG. 6A, the system 52 includes four BLP units 13 docked to an off-line binning process tool 54.

FIGS. 6B and 6C illustrate the mechanical and electrical interface points of the modular system shown in FIG. 6A. As noted above, the BLP unit 13 may modularly interface with a variety of external devices, such as the offline binning process tool 54 shown in FIGS. 6A and 6B. As shown in FIG. 6B, the offline binning process tool 54 includes a set of mechanical coupling points 76 a-c for each BLP to be interfaced. In the embodiment illustrated in FIG. 6B, the offline binning process tool 54 is provided with three mechanical coupling points 76 a-c to ensure proper alignment of the BLP with the process tool 54. Additional couplings may be provided for other functions. For example, an electrical and pneumatic coupling 78 may be provided to interface the electrical and pneumatic subsystems of the BLP with those of the process tool 54.

As shown in FIG. 6C, each BLP 13 is provided with interface points corresponding to the interface points of the external devices with which the BLP can modularly interface. In the embodiment illustrated in FIG. 6C, the BLP is adapted to interface with an external device having interface points similar to those provided on the offline-binning process tool 54 shown in FIG. 6B. In this regard, the BLP 13 is provided with mechanical couplings 80 a-c to correspond to the mechanical couplings 76 a-c on the process tool 54 of FIG. 6B. Further, an electrical and pneumatic coupling 82 is provided on the BLP 13 to interface with the electrical and pneumatic coupling 78 of the process tool 54 of FIG. 6B. Thus, the interfacing of the BLP with any number of devices can be easily achieved in a modular fashion through a common set of couplings for various subsystems.

FIGS. 7A and 7B illustrate front and side views, respectively, of an elevator mechanism 56 used to position trays and category separator plates in a vertical stack. Conventional systems use mechanical components to constrain and move support shelves for each sort category. Mechanisms are provided to move and support the shelves vertically, as well as mechanism to move and support a category support latch. In this regard, multiple motors and support rails may be required. As illustrated in FIGS. 7A and 7B, the illustrated embodiment requires only one bearing rail 50 and a single ball screw 58 to raise and lower all plates and trays.

FIGS. 8A-8L are front views illustrated to describes the positioning and movement of the various mechanisms during certain operations, such as loading, sorting and unloading. Four categories of trays are illustrated, including categories 1-3 and untested. It will be understood by those skilled in the art that the system may be adapted to accommodate any number of categories.

FIG. 8A illustrates the system as it may appear at initial start-up with no trays in the system. In the illustrated embodiment, the elevator 38 is provided to move in the vertical direction and to support a plurality of trays (none shown in FIG. 8A) and separator plates 64 a-d. The tray load arm 34 is provided to move horizontally at a fixed height. The tray load arm 34 is provided with a tray support mechanism, such as retractable support fingers 60, for supporting one or more trays. The plate lock mechanism 40 is positioned at a fixed height above the height of the tray load arm 34. The plate lock mechanism 40 is adapted to secure a category separator plate 64 a-d or a tray with retractable latches 62 adapted to engage latch receivers 66 formed in the category separator plates 64 a-d or features formed in the trays or separator plates.

Referring now to FIG. 8B, when an operator loads a stack of trays containing untested devices, the elevator 38 moves into a position which allows the latches 62 of the plate lock mechanism 40 to engage the separator plate 64 a marked “UNTESTED”. The latches 62 are moved to engage the separator plate 64 a, which supports additional separator plates 64 b-d, and the elevator 38 then moves downward to a position below the tray load arm 34, as shown in FIG. 8B. The support fingers 60 are extended such that a platform is provided on which to a stack of trays 68 is supported.

Referring now to FIG. 8C, the elevator 38 moves upward until the stack of trays 68 is lifted by the elevator 38. The support fingers 60 then retract, and the stack 68 is fully supported by the elevator 38.

In certain embodiments, a number of trays may be included in a stack carried by the tray load arm 34. In this regard, in certain embodiments, a full complement of input trays may require multiple input cycles. In these cases, as shown in FIG. 8D, the elevator may lower such that the stack of trays 68 is at a position such that the top tray in the stack 68 is positioned below the load arm 34. An additional stack of trays 69 may then be input to be added to the stack of trays 68 already supported by the elevator.

Referring now to FIG. 8E, a tray 68 a from the stack of trays 68 is provided to a device tester, for example. When the device tester requests a tray of untested devices from the BLP, the elevator 38 will position the stack of trays to a position where the support fingers 60 can engage the top tray 68 a in the stack 68. With the top tray 68 a being supported by the support fingers 60, the elevator moves downward. The top tray 68 a can then be transported to the device handler into one of the tray locating stations described above with reference to FIG. 2, for example, via the tray-handling shuttle. Additional trays may be provided to the device handler or the tester in a similar manner until either all trays in the stack 68 have been delivered or a sorted tray is required to be inserted into the BLP.

Referring now to FIG. 8F, the device handler may request to place a tray of tested and sorted devices back into the BLP in a certain category location. The elevator 38 raises the stack of trays 68 until the stack 68 lifts the separator plates 64 a-d above the plate lock mechanism 40. At this point, the latches 62 of the lock mechanism 40 are retracted and disengage from the separator plate 64 a.

Referring now to FIG. 8G, the system prepares to receive a tested and sorted tray 70 belonging to category 2. The elevator 38 moves downward until the separator plate 64 c labeled “CATEGORY 2” is positioned to be supported by the plate lock mechanism 40. At this point, the latches 62 engage the separator plate 64 c, and the elevator 38 moves downward with other category separator plates 64 a-b on top of the stack of untested trays 68. The elevator moves down far enough so that the top tray or separator plate supported by the elevator is below the height of the tray load arm 34, as shown in FIG. 8G. The tested tray 70 can then be moved into position, supported by the support fingers 60. The elevator 38 may now move upward to support the tested tray 70, allowing the support fingers 60 to retract.

It is noted that, although FIG. 8G shows the tested tray 70 as belonging to “CATEGORY 2”, the disclosed system does not require pre-assignment of the categories. Specifically, the allocation and assignment of the categories and the separator plates 64 a-d can be performed dynamically. Thus, for example, the first separator plate 64 a may be assigned to the first tested tray, regardless of the actual characteristics of the devices associated with the first tested tray. A second tested tray may be allocated to the first category tray 64 a if the characteristics of the devices in the second tray correspond to those in the first tested tray. Otherwise, the second separator plate 64 b may be dynamically assigned to the category of the second tested tray. This process may be repeated to categorize all trays to be tested. For certain embodiments, the sorting of the tested trays can be achieved without the use of separator plates 64 a-d. In those embodiments, tested trays belonging to a category are positioned next to each other. The separation of categories can be tracked by a processor within or outside the BLP.

Referring now to FIG. 8H, the next untested tray 68 b from the stack of trays 68 is now positioned to be delivered to the device handler for testing. The elevator 38 moves upward until the separator plate 64 a labeled “UNTESTED” can be engaged by the latches 62. The elevator 38 then moves downward until the support fingers 60 can remove the untested tray 68 b from the stack 68, as shown in FIG. 8H.

Referring now to FIG. 8I, when all the trays of untested devices in the stack 68 have been tested, trays of sorted devices are positioned appropriately. As shown in FIG. 8I, each category of trays is positioned in a stack below a category separator plate identifying the stack. Thus, a stack of trays 70 a belonging to category 1 are positioned above or below (below in the example illustrated in FIG. 8I) the separator plate 64 b labeled “CATEGORY 1.” Other stacks 70 b, 70 c are similarly positioned below corresponding separator plates 64 c, 64 d, respectively.

Referring now to FIG. 8J, the sorted trays may now be unloaded by an operator. As an example, FIG. 8J illustrates the unloading of trays belonging to category 2. The elevator 38 moves upward until the separator plate 64 c labeled “CATEGORY 2” can be engaged by the latches 62. Once the separator plate 64 c is supported by the latches 62, the elevator 38 moves downward until the bottom tray in the stack 70 b of category 2 trays can be supported by the support fingers 60. The support fingers 60 then extend and capture the bottom tray in the sorted stack 70 b, and the elevator 38 moves downward. The tray load arm 34 can then move the stack 70 b horizontally for access by the operator.

FIGS. 8K and 8L illustrate an unloading operation in which the number of trays in a stack to be unloaded are greater than the capacity of either the tray load arm 34 or another component in the system. In this case, the elevator 38 moves to a position such that the maximum capacity of trays of the stack 70 a is positioned above the support fingers 60. The support fingers 60 then extend to support the maximum capacity of trays, an the elevator 38 moves downward with the remaining trays. Thus, the stack 70 a of sorted category 1 trays is divided into two stacks 70 a-1, 70 a-2, of which one stack 70 a-1 is supported by the support fingers 60 and the other stack 70 a-2 is supported by the elevator, as illustrated in FIG. 8K. Once the first of these stacks 70 a-1 has been unloaded by the operator, the elevator 38 moves upward to allow the support fingers 60 to support the remaining stack 70 a-2. The elevator 38 then moves downward, and the remaining stack 70 a-2 can then be unloaded by the operator.

It is important to note that the separator plates 64 a-d provide a visual guide of the categories of various trays. The separator plates 64 a-d are not required for operation of the embodiments of the invention. In certain embodiments, the separator plates 64 a-d may be eliminated, and a processor may track the boundaries between various categories. In such an arrangement, the plate lock mechanism 40 is capable of supporting the trays, rather than the separator plates.

The description of FIGS. 8A-8L corresponds to a BLP unit for use as shown in FIG. 2. It is noted that similar processes may be performed in an embodiment such as that illustrated in FIG. 3. In this regard, a pick-and-place mechanism may interact directly with trays positioned on, for example, the support fingers.

FIG. 9 illustrates an embodiment of a device tray 27 for use with embodiments of the invention. The tray 27 may be provided with a number of slots in which devices, such as an electronic device 72, can be positioned. The device tray 27 may be formed of any of a number of materials, such as a rigid plastic.

FIG. 10 illustrates category separator plates for use with embodiments of the present invention. The separator plates 64 are provided with the latch receiver 66 for engaging a latch 60 of the plate lock mechanism 40 (FIG. 8A). The plates 64 are provided with a substantially flat surface 74 for supporting the device trays. The plates 64 may be made of a light-weight material, such as aluminum, which is capable of supporting a desired number of trays.

The foregoing includes description of certain embodiments of the BLP. Those skilled in the art will recognize that BLP's may be configured in a variety of ways. For example, as noted above, BLP's may be configured with any type of trays having any number of devices, lot separator plates or empty trays, for example. Such variations are contemplated within the scope of the invention.

The foregoing description of embodiments of the invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variation are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modification as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. 

1. An apparatus for handling devices adapted to be assigned to one of a plurality of categories, comprising: an elevator adapted to move a stack of trays along a vertical path; and a locking mechanism adapted to selectively and directly secure a tray in said stack of trays and to support said engaged tray and any additional trays positioned above said engaged tray.
 2. The apparatus according to claim 1, wherein the trays in said stack of trays include device trays and separator plates.
 3. The apparatus according to claim 1, further comprising: a tray load arm positioned at a fixed vertical position and having a support mechanism for supporting one or more trays, said tray load arm being adapted to move horizontally into and out of said vertical path.
 4. The apparatus according to claim 3, wherein the tray load arm is adapted to provide trays to and receive trays from an operator for unloading and loading the apparatus.
 5. The apparatus according to claim 3, wherein the tray load arm is adapted to provide trays to and receive trays from an external device for unloading and loading the apparatus in an automated manner.
 6. The apparatus according to claim 3, wherein the tray load arm is adapted to provide trays to and receive trays from an external device for processing of the trays.
 7. The apparatus according to claim 6, wherein the external device is a device handler having a tray-handling shuttle.
 8. The apparatus according to claim 3, wherein the tray load arm is adapted to position a desired tray to provide access to individual devices on said desired tray to an external device.
 9. The apparatus according to claim 8, wherein the external device includes a pick-and-place mechanism.
 10. The apparatus of claim 3, further comprising: a processor adapted to control said elevator, said locking mechanism and said tray load arm to sort devices in said trays according to a plurality of categories.
 11. The apparatus of claim 1, further comprising: a modular interface adapted to allow the apparatus to modularly interface with an external device.
 12. The apparatus of claim 11, wherein the modular interface comprises: one or more mechanical couplings adapted to mechanically align the apparatus with the external device; and one or more subsystem couplings, each subsystem coupling being adapted to couple a subsystem of the apparatus with a corresponding subsystem of the external device.
 13. An apparatus for handling devices adapted to be assigned to one of a plurality of categories, comprising: means for moving a stack of trays along a vertical path; and means for selectively and directly securing a tray in said stack of trays and for supporting said engaged tray and any additional trays positioned above said engaged tray.
 14. The apparatus according to claim 13, wherein the trays in said stack of trays include device trays and separator plates.
 15. The apparatus according to claim 13, further comprising: means for moving a stack of trays horizontally into and out of said vertical path, said means for moving being positioned at a fixed vertical position and having a support mechanism for supporting one or more trays.
 16. The apparatus according to claim 15, wherein the means for moving a stack of trays horizontally is adapted to provide trays to and receive trays from an operator for unloading and loading the apparatus.
 17. The apparatus according to claim 16, wherein the means for moving a stack of trays horizontally is adapted to provide trays to and receive trays from an external device for unloading and loading the apparatus in an automated manner.
 18. The apparatus according to claim 15, wherein the means for moving a stack of trays horizontally is adapted to provide trays to and receive trays from an external device for processing of the trays.
 19. The apparatus according to claim 18, wherein the external device is a device handler having a tray-handling shuttle.
 20. The apparatus according to claim 15, wherein the means for moving a stack of trays horizontally is adapted to position a desired tray to provide access to individual devices on said desired tray to an external device.
 21. The apparatus according to claim 20, wherein the external device includes a pick-and-place mechanism.
 22. The apparatus of claim 13, further comprising: means for modularly interfacing the apparatus with an external device.
 23. The apparatus of claim 22, wherein the means for modularly interfacing comprises: means for mechanically aligning the apparatus with the external device; and means for coupling a subsystem of the apparatus with a corresponding subsystem of the external device.
 24. A method of sorting a tray of devices adapted to be assigned to one of a plurality of categories, comprising: receiving a sorted tray of devices assigned to one of said categories; determining a sort position for said sorted tray in a stack of trays on a platform; vertically moving said platform to align a locking mechanism with an upper tray in said stack, said upper tray being immediately above said sort position; locking said upper tray with said locking mechanism; vertically moving said platform to position a lower tray below a load arm having said sorted tray, said lower tray being immediately below said sort position; and placing said sorted tray on said lower tray on said platform.
 25. The method according to claim 24, wherein at least one of said upper tray and said lower tray is a separator plate.
 26. A program product, comprising machine readable program code for causing a machine to perform the following method steps: receiving a sorted tray of devices assigned to one of said categories; determining a sort position for said sorted tray in a stack of trays on a platform; vertically moving said platform to align a locking mechanism with an upper tray in said stack, said upper tray being immediately above said sort position; locking said upper tray with said locking mechanism; vertically moving said platform to position a lower tray below a load arm having said sorted tray, said lower tray being immediately below said sort position; and placing said sorted tray on said lower tray on said platform.
 27. The program product according to claim 26, wherein at least one of said upper tray and said lower tray is a separator plate.
 28. A system for sorting a tray of devices adapted to be assigned to one of a plurality of categories, comprising: means for receiving a sorted tray of devices assigned to one of said categories; means for determining a sort position for said sorted tray in a stack of trays on a platform; means for vertically moving said platform to align a locking mechanism with an upper tray in said stack, said upper tray being immediately above said sort position; means for locking said upper tray with said locking mechanism; means for vertically moving said platform to position a lower tray below a load arm having said sorted tray, said lower tray being immediately below said sort position; and means for placing said sorted tray on said lower tray on said platform.
 29. A method of sorting a device adapted to be assigned to one of a plurality of categories, comprising: receiving a sorted device assigned to one of said categories; determining a sort tray for said sorted device in a stack of trays on a platform; vertically moving said platform to align a locking mechanism with an upper tray in said stack immediately above said sort tray; locking said upper tray with said locking mechanism; vertically moving said platform to position said sort tray in a loading position; and placing said sorted tray on said lower tray on said platform.
 30. A system for sorting a device adapted to be assigned to one of a plurality of categories, comprising: means for receiving a sorted device assigned to one of said categories; means for determining a sort tray for said sorted device in a stack of trays on a platform; means for vertically moving said platform to align a locking mechanism with an upper tray in said stack immediately above said sort tray; means for locking said upper tray with said locking mechanism; means for vertically moving said platform to position said sort tray in a loading position; and means for placing said sorted tray on said lower tray on said platform. 